Bronchial Catarrh. 55 



passages, while eating, may likewise irritate the mucosa more 

 or less. Non-acrid, non-corroding and pure fluids are less 

 dangerous since they are rapidly absorbed by the mucosa, as 

 was shown by intratracheal injections. However, dried par- 

 ticles are often contaminated with saprophytic and other bac- 

 teria and they cannot easily be removed from the bronchi. 

 Since substances are often aspirated in difficult deglutition, 

 pharyngitis, paralysis of the pharynx or unconsciousness, these 

 conditions also often lead to bronchial catarrh ; aspiration may 

 also occur when fluids are poured in in an awlovard manner. 

 Larger foreign bodies (stones, ears of cereals, needles, etc.) 

 may exceptionally get into the bronchi. 



* Bronchial catarrh undoubtedly also owes its origin to an 

 infection, and it is then liable to assume an enzootic character. 

 Under this type are to be mentioned the common contagious 

 bronchial catarrhal affections seen in studs, among army horses, 

 described under the designation of enzootic catarrh of the 

 respiratory tract. Its true nature, however, is up to date not 

 vet known (see page 43). The bacillus pyocyaneus frequently 

 causes enzootic, purulent bronchial catarrh in young pigs and 

 in cattle. Other forms of enzootic infectious bronchial catarrh 

 however occur likewise in cattle and in goats. (Pr. Vb., Grimm, 

 Martens, Lewek, Eeisinger.) The bronchial catarrh observed 

 by Schmidt in cattle in transit may likewise be due to an in- 

 fection. (For further details see the chapter on .catarrhal 

 pneumonia.) 



Secondary bronchial catarrh is quite common, particularly 

 in connection with diseases of the lungs. Rarely, however, does 

 inflammation of the larynx or trachea extend to the mucosa 

 of the bronchi. 



Finally bronchial catarrh is frequently seen as a part of 

 the clinical picture of specific infectious diseases (strangles, 

 hemorrhagic septicemia, smallpox, foot-and-mouth disease, dis- 

 temper, etc.). 



Chronic bronchial catarrh is caused by the same factors 

 which bring about the acute form if the detrimental cause acts 

 permanently or if it leads to repeated attacks of the acute form. 

 However, even then the affection of the bronchi is more com- 

 monly secondary in nature. Every continuous disturbance _ of 

 the respiratory mechanism or of the pulmonary circulation 

 brings about chronic bronchial catarrh, because not only de- 

 ficient ventilation of the air passages and the decomposition 

 of mucus due to it but also stasis of blood will cause a dis- 

 turbance of nutrition of the mucosa. Consequently a bronchial 

 catarrh is almost always seen accompanying chronic pulmonary 

 emphysema, chronic interstitial pneumonia, organic heart dis- 

 ease, and chronic infectious diseases affecting the lungs (tuber- 

 culosis, glanders, actinomycosis, etc.). Animal parasites may 

 also produce chronic bronchial catarrh (see lungworm disease). 



